An alien hunter says he has caught a UFO on camera with a police helicopter chasing it.

Chris Martin, 42, was telephoned at home by his sister, Patricia Roberts, who was watching events unfold from her back garden at around 9.30pm.

He rushed to Prince of Wales Road, Blackheath, near Mrs Robert's Lochaber Road home, where he says he saw a flying object being tracked by the chopper nearby.

Mr Martin, of Patrick Connolly Gardens, Bromley-By-Bow, says he filmed the helicopter focusing its searchlight on a light-emitting flying object.

The father-of-one told News Shopper: "I can't say what it was, but it should not have been there, and was definitely a UFO.

"The police helicopter seemed to be chasing it and shining its searchlight onto it. I believe they were sent out to intercept the craft."

Martian-mad Mr Martin gave up his job as a session guitarist to study UFO sightings and suspected alien visits full-time in 1997. The extraterrestrial enthusiast, who had a book on the subject published in 2000, says the aliens do not come here just to see the sights.

He said: "I believe in life on other planets and I believe they visit us regularly in their alien craft.

"They come to collect information and gather genetic material by abducting humans and animals."

Mr Martin added: "The aliens are using their advanced technology to create hybrid species."

But police have denied any knowledge of UFOs in the area and have told News Shopper the helicopter was tracking a less unusual target on April 8.

A spokesman for Greenwich police said: "A police helicopter was in the air, in that area and at that time, because of a traffic collision.

"A person was seen running away from one of the cars involved and a helicopter was sent up to help in the search for the man who was never traced.

"We were not responding to any reports of UFOs in the Blackheath area."